SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '91bdf20a68c6f1cea5fa394524fa388e3bc5aad5a4762b792fd54ac7f8962b67' 
  AND token = 'xgBkOZzn8Jsda9kGV6gOEKDVcyYzFqGn23BeIlsX8dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}